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©Ian Sommerville 2004 Software Engineering, 7th edition. Chapter 5 Slide 2
Topics covered
Management activities Project planning Project scheduling Risk management
©Ian Sommerville 2004 Software Engineering, 7th edition. Chapter 5 Slide 3
Concerned with activities involved in ensuring that software is delivered on time and on schedule and in accordance with the requirements of the organisations developing and procuring the software.
Project management is needed because software development is always subject to budget and schedule constraints that are set by the organisation developing the software.
Software project management
©Ian Sommerville 2004 Software Engineering, 7th edition. Chapter 5 Slide 4
The product is intangible. The product is uniquely flexible. Software engineering is not recognized as an
engineering discipline with the sane status as mechanical, electrical engineering, etc.
The software development process is not standardised.
Many software projects are 'one-off' projects.
Software management distinctions
©Ian Sommerville 2004 Software Engineering, 7th edition. Chapter 5 Slide 5
Proposal writing. Project planning and scheduling. Project costing. Project monitoring and reviews. Personnel selection and evaluation. Report writing and presentations.
Management activities
©Ian Sommerville 2004 Software Engineering, 7th edition. Chapter 5 Slide 6
Project staffing
May not be possible to appoint the ideal people to work on a project• Project budget may not allow for the use of
highly-paid staff;• Staff with the appropriate experience may not
be available;• An organisation may wish to develop employee
skills on a software project. Managers have to work within these constraints
especially when there are shortages of trained staff.
©Ian Sommerville 2004 Software Engineering, 7th edition. Chapter 5 Slide 7
Project planning
Probably the most time-consuming project management activity.
Continuous activity from initial concept through to system delivery. Plans must be regularly revised as new information becomes available.
Various different types of plan may be developed to support the main software project plan that is concerned with schedule and budget.
©Ian Sommerville 2004 Software Engineering, 7th edition. Chapter 5 Slide 8
Types of project plan
Plan Description
Quality plan Describes the quality procedures and standards that will beused in a project. See Chapter 27.
Validation plan Describes the approach, resources and schedule used forsystem validation. See Chapter 22.
Configurationmanagement plan
Describes the configuration management procedures andstructures to be used. See Chapter 29.
Maintenance plan Predicts the maintenance requirements of the system,maintenance costs and effort required. See Chapter 21.
Staff developmentplan.
Describes how the skills and experience of the project teammembers will be developed. See Chapter 25.
©Ian Sommerville 2004 Software Engineering, 7th edition. Chapter 5 Slide 9
Project planning process
Establish the project constraints Make initial assessments of the project parameters Define project milestones and deliverableswhile project has not been completed or cancelled loop
Draw up project scheduleInitiate activities according to schedule
Wait ( for a while ) Review project progress Revise estimates of project parameters Update the project schedule Re-negotiate project constraints and deliverables if ( problems arise ) then Initiate technical review and possible revision end ifend loop
©Ian Sommerville 2004 Software Engineering, 7th edition. Chapter 5 Slide 10
The project plan
The project plan sets out:• The resources available to the project;• The work breakdown;• A schedule for the work.
©Ian Sommerville 2004 Software Engineering, 7th edition. Chapter 5 Slide 11
Project plan structure
Introduction. Project organisation. Risk analysis. Hardware and software resource
requirements. Work breakdown. Project schedule. Monitoring and reporting mechanisms.
©Ian Sommerville 2004 Software Engineering, 7th edition. Chapter 5 Slide 12
Activity organization
Activities in a project should be organised to produce tangible outputs for management to judge progress.
Milestones are the end-point of a process activity.
Deliverables are project results delivered to customers.
The waterfall process allows for the straightforward definition of progress milestones.
©Ian Sommerville 2004 Software Engineering, 7th edition. Chapter 5 Slide 13
Milestones in the RE process
Evaluationreport
Prototypedevelopment
Userrequirements
Requirementsanalysis
Feasibilityreport
Feasibilitystudy
Architecturaldesign
Designstudy
Systemrequirements
Requirementsspecification
ACTIVITIES
MILESTONES
©Ian Sommerville 2004 Software Engineering, 7th edition. Chapter 5 Slide 14
Project scheduling
Split project into tasks and estimate time and resources required to complete each task.
Organize tasks concurrently to make optimal use of workforce.
Minimize task dependencies to avoid delays caused by one task waiting for another to complete.
Dependent on project managers intuition and experience.
©Ian Sommerville 2004 Software Engineering, 7th edition. Chapter 5 Slide 15
The project scheduling process
Estimate resourcesfor activities
Identify activitydependencies
Identifyactivities
Allocate peopleto activities
Softwarerequirements
Activity chartsand bar charts
Create projectcharts
©Ian Sommerville 2004 Software Engineering, 7th edition. Chapter 5 Slide 16
Bar charts and activity networks
Graphical notations used to illustrate the project schedule.
Show project breakdown into tasks. Tasks should not be too small. They should take about a week or two.
Activity charts show task dependencies and the the critical path.
Bar charts show schedule against calendar time.
©Ian Sommerville 2004 Software Engineering, 7th edition. Chapter 5 Slide 17
Task durations and dependencies
Activity Duration (days) Dependencies
T1 8
T2 15
T3 15 T1 (M1)
T4 10
T5 10 T2, T4 (M2)
T6 5 T1, T2 (M3)
T7 20 T1 (M1)
T8 25 T4 (M5)
T9 15 T3, T6 (M4)
T10 15 T5, T7 (M7)
T11 7 T9 (M6)
T12 10 T11 (M8)
©Ian Sommerville 2004 Software Engineering, 7th edition. Chapter 5 Slide 18
Activity network
start
T2
M3T6
Finish
T10
M7T5
T7
M2T4
M5
T8
4/7/03
8 days
14/7/03 15 days
4/8/03
15 days
25/8/03
7 days
5/9/03
10 days
19/9/03
15 days
11/8/03
25 days
10 days
20 days
5 days25/7/03
15 days
25/7/03
18/7/03
10 days
T1
M1 T3T9
M6
T11
M8
T12
M4
©Ian Sommerville 2004 Software Engineering, 7th edition. Chapter 5 Slide 19
Activity timeline4/7 11/7 18/7 25/7 1/8 8/8 15/8 22/8 29/8 5/9 12/9 19/9
T4
T1T2
M1
T7T3
M5
T8
M3
M2
T6
T5
M4
T9
M7
T10
M6
T11M8
T12
Start
Finish
©Ian Sommerville 2004 Software Engineering, 7th edition. Chapter 5 Slide 20
Staff allocation
4/7 11/7 18/7 25/7 1/8 8/8 15/8 22/8 29/8 5/9 12/9 19/9
T4
T8 T11
T12
T1
T3
T9
T2
T6 T10
T7
T5
Fred
Jane
Anne
Mary
Jim
©Ian Sommerville 2004 Software Engineering, 7th edition. Chapter 5 Slide 21
Risk management
Risk management is concerned with identifying risks and drawing up plans to minimise their effect on a project.
A risk is a probability that some adverse circumstance will occur • Project risks affect schedule or resources;• Product risks affect the quality or
performance of the software being developed;
• Business risks affect the organisation developing or procuring the software.
©Ian Sommerville 2004 Software Engineering, 7th edition. Chapter 5 Slide 22
Software risks
Risk Affects Description
Staff turnover Project Experienced staff will leave the project before it is finished.
Management change Project There will be a change of organisational management withdifferent priorities.
Hardware unavailability Project Hardware that is essential for the project will not bedelivered on schedule.
Requirements change Project andproduct
There will be a larger number of changes to therequirements than anticipated.
Specification delays Project andproduct
Specifications of essential interfaces are not available onschedule
Size underestimate Project andproduct
The size of the system has been underestimated.
CASE tool under-performance
Product CASE tools which support the project do not perform asanticipated
Technology change Business The underlying technology on which the system is built issuperseded by new technology.
Product competition Business A competitive product is marketed before the system iscompleted.
©Ian Sommerville 2004 Software Engineering, 7th edition. Chapter 5 Slide 23
Risks and risk types
Risk type Possible risks
Technology The database used in the system cannot process as many transactions per secondas expected.Software components that should be reused contain defects that limit theirfunctionality.
People It is impossible to recruit staff with the skills required.Key staff are ill and unavailable at critical times.Required training for staff is not available.
Organisational The organisation is restructured so that different management are responsible forthe project.Organisational financial problems force reductions in the project budget.
Tools The code generated by CASE tools is inefficient.CASE tools cannot be integrated.
Requirements Changes to requirements that require major design rework are proposed.Customers fail to understand the impact of requirements changes.
Estimation The time required to develop the software is underestimated.The rate of defect repair is underestimated.The size of the software is underestimated.
©Ian Sommerville 2004 Software Engineering, 7th edition. Chapter 5 Slide 24
Risk analysis (i)
Risk Probability Effects
Organisational financial problems force reductions inthe project budget.
Low Catastrophic
It is impossible to recruit staff with the skills requiredfor the project.
High Catastrophic
Key staff are ill at critical times in the project. Moderate Serious
Software components that should be reused containdefects which limit their functionality.
Moderate Serious
Changes to requirements that require major designrework are proposed.
Moderate Serious
The organisation is restructured so that differentmanagement are responsible for the project.
High Serious
©Ian Sommerville 2004 Software Engineering, 7th edition. Chapter 5 Slide 25
Risk analysis (ii)
Risk Probability Effects
The database used in the system cannot process asmany transactions per second as expected.
Moderate Serious
The time required to develop the software isunderestimated.
High Serious
CASE tools cannot be integrated. High Tolerable
Customers fail to understand the impact ofrequirements changes.
Moderate Tolerable
Required training for staff is not available. Moderate Tolerable
The rate of defect repair is underestimated. Moderate Tolerable
The size of the software is underestimated. High Tolerable
The code generated by CASE tools is inefficient. Moderate Insignificant
©Ian Sommerville 2004 Software Engineering, 7th edition. Chapter 5 Slide 26
Risk management strategies (i)
Risk Strategy
Organisationalfinancial problems
Prepare a briefing document for senior managementshowing how the project is making a very importantcontribution to the goals of the business.
Recruitmentproblems
Alert customer of potential difficulties and thepossibility of delays, investigate buying-incomponents.
Staff illness Reorganise team so that there is more overlap of workand people therefore understand each other’s jobs.
Defectivecomponents
Replace potentially defective components with bought-in components of known reliability.
©Ian Sommerville 2004 Software Engineering, 7th edition. Chapter 5 Slide 27
Risk management strategies (ii)
Risk Strategy
Requirementschanges
Derive traceability information to assess requirementschange impact, maximise information hiding in thedesign.
Organisationalrestructuring
Prepare a briefing document for senior managementshowing how the project is making a very importantcontribution to the goals of the business.
Databaseperformance
Investigate the possibility of buying a higher-performance database.
Underestimateddevelopment time
Investigate buying in components, investigate use of aprogram generator
©Ian Sommerville 2004 Software Engineering, 7th edition. Chapter 5 Slide 28
Risk indicators
Risk type Potential indicators
Technology Late delivery of hardware or support software, many reportedtechnology problems
People Poor staff morale, poor relationships amongst team member,job availability
Organisational Organisational gossip, lack of action by senior management
Tools Reluctance by team members to use tools, complaints aboutCASE tools, demands for higher-powered workstations
Requirements Many requirements change requests, customer complaints
Estimation Failure to meet agreed schedule, failure to clear reporteddefects